ABSTRACT
The effect of restoration of mesio-occluso-distal cavities in molar teeth with reinforced glass ionomer cements on cuspal flexure in vitro is reported. Measurements of cuspal flexure using linear variable displacement transducers were carried out for 90 min after the placement of two types of reinforced glass ionomer cement. The measurements demonstrated that no movement occurred except in cases where the materials were allowed to dehydrate. Under these circumstances the opposing cusps moved toward one another. This movement was observed to be directly related to time. Microleakage was very much less than that observed for composite materials evaluated under the same test conditions.
Subject(s)
Dental Amalgam/chemistry , Glass Ionomer Cements/chemistry , Composite Resins/chemistry , Dental Caries/therapy , Dental Leakage , Dental Restoration, Permanent/methods , Glass Ionomer Cements/therapeutic use , Humans , Materials Testing , Silver/chemistryABSTRACT
Problems related to leakage have been observed with direct-filled composite restorations. The development of indirect system of fabrication followed by cementation should theoretically reduce this phenomenon. The present study compares the leakage around directly placed composites with composite inlays prepared by a surgery-based system. The results indicate that the amount of leakage is reduced with the inlay system, but that it is not eliminated.
Subject(s)
Composite Resins/chemistry , Dental Leakage/diagnosis , Dental Restoration, Permanent , Inlays , Acrylic Resins/chemistry , Coloring Agents , Dental Bonding , Dental Cavity Lining , Dental Cavity Preparation/methods , Dental Cements/chemistry , Dental Cementum/ultrastructure , Dental Enamel/ultrastructure , Dental Leakage/prevention & control , Dental Restoration, Permanent/methods , Humans , Polyurethanes/chemistry , Surface Properties , TemperatureABSTRACT
The presence of an interface gap around the periphery of old amalgam restorations in extracted teeth was confirmed by scanning electron microscopy (SEM) and light microscopy. Two fissure sealant resins (Concise White Sealant and Delton Fissure Sealant) were placed over amalgam margins in vitro and were found to occlude this gap. SEM studies permitted assessment of the integrity of the resin in the interface defect and degree of sealant penetration toward the enamel/dentine junction. Microleakage studies using dye immersion techniques confirmed the efficacy of sealants in limiting dye penetration. This study indicates that margins of amalgams may be sealed in vivo by this method, delaying the need for replacement of the old amalgam and potentially providing protection for the tooth from secondary marginal caries.
